In the recent decades, increased focus has been directed to the exploitation of renewable energy sources. Wave energy is a renewable energy resource created by large storms hundreds of kilometers offshore that generate and transmit huge amounts of energy that travels great distances (via swell) and mixes with local influences (seas) to arrive at our shores. It is a genuinely renewable energy source and distinct from tidal energy. Wave energy as a renewable energy source has a number of advantages. One advantage is the high power density of wave energy that suggests it has the capacity to become the lowest cost renewable energy source. A further advantage is the predictability of wave energy: unlike solar and wind, wave energy levels can be predicted many days in advance, making it less challenging to integrate wave energy with national power supplies.
A major challenge of the exploitation of wave energy is to optimize energy production year round, including increasing the efficiency of the energy absorption, harvesting energy under varying wave conditions, maximizing production up-time of a wave energy plant, and minimizing the cost of energy production.
A wave energy plant using absorbers of the front pivot type is disclosed in DK 174 463 B1 where a plurality of front pivot absorber elements are pivotally attached to a submerged platform to swing around a horizontal pivot axis arranged at the front of the absorber element. Under operation, incoming waves travel from the front end towards a rear end of the absorber element interacting with it to absorb both kinetic and potential energy from the waves. The resulting motion of the absorber element with respect to the platform frame is exploited by a hydraulic power take-off system. The disclosed absorber element comprises a floating body with a closed top and an open bottom and may further be divided into cells with perforated walls acting as flow resistance for water flowing into and out of the floating body.